Gas-phase reactors, such as chemical vapor deposition (CVD), plasma-enhanced CVD (PECVD), atomic layer deposition (ALD), and the like can be used for a variety of applications, including depositing and etching materials on a substrate surface. For example, gas-phase reactors can be used to deposit and/or etch layers on a substrate to form semiconductor device, flat panel display devices, photovoltaic devices, microelectromechanical systems (MEMS), and the like.
A typical gas-phase reactor system includes a reactor including a reaction chamber, one or more precursor gas sources fluidly coupled to the reaction chamber, one or more carrier or purge gas sources fluidly coupled to the reaction chamber, a gas distribution system to deliver gasses (e.g., the precursor gas(ses) and/or carrier or purge gas(ses)) to a surface of a substrate, and an exhaust source fluidly coupled to the reaction chamber. The system also typically includes a susceptor to hold a substrate in place during processing. The susceptor can be configured to move up and down to receive a substrate and/or can rotate during substrate processing.
Generally, it is desirable to have uniform film properties (e.g., film thickness and resistivity) across a surface of a substrate. Various gas distribution systems have been developed to attempt to achieve uniform or substantially uniform film properties. For example, gas distribution systems including multiple ports (e.g., up to 5) or nozzles located within the reaction chamber have been developed to increase uniformity of film properties across a substrate surface. However, such systems do not adequately address uniformity of film properties, particularly at or near an edge of a substrate. Additionally, such systems generally do not allow for independent control of film properties, such as film thickness uniformity and resistivity.
As sizes of features formed on a substrate surface decrease, it becomes increasingly important to control film properties, including film thickness and resistivity. Moreover, it may be desirable to independently tune film properties; e.g., to independently tune film thickness uniformity and resistivity in layers deposited using gas-phase reactors, such as epitaxial layers grown using such reactors. Accordingly improved gas distribution systems, reactor systems including an improved gas distribution system, and methods of using the gas distribution and reactor systems are desired.